Image display apparatuses, such as digital cameras, video cameras, televisions, mobile phones, TV game devices, and color printers, are provided with image processing apparatuses that convert input images to output images having shitsukan different from that of the input images. Such an image processing apparatus is provided with a program for regular shitsukan adjustment, such as skin-color adjustment, that can be ran by a computer, such as a microcomputer or a high-speed logic element.
An image processing program for individually changing and adjusting physical image characteristics of an original image is put to practical use. The program enables such change and adjustment by inputting an image to a personal computer and manually setting various parameters of the image via a screen. Such a program may provide various filtering effects and improve image shitsukan by simultaneously changing various different image characteristics (such as brightness, hue, saturation, gradation, and frequency) that are linked together.
Unfortunately, it is difficult for an average user to acquire desired shitsukan in an input image by changing the individual image characteristics and selecting optimal filtering processes for the input image. When at least two image characteristics are interactively changed, it is difficult to presume the interactive result of such change, and it is even more difficult to presume the level of change in the image shitsukan before and after image processing.
PTL 1 describes an image processing apparatus that improves sensuous image quality. Multiple image characteristics are grouped in advance on the basis of the sensuous effect they provided, such as shitsukan, softness, and brightness, and are linked together so that they are interactively changed.